Advice on knock through and RSJ

[togauk]

Just wondered if anyone had seen this before and had any advice.

I'm in a 1950s house and at some point it looks like the wall between the dining room and lounge was knocked through - no idea when (I'm assuming it wasn't built like this). It's since been boarded back up with plasterboard on both sides.

I took away part of the plasterboard as we were thinking of opening it up but didn't find an rsj in there. I had a structural engineer over for something else and showed him and his advice was to get it propped and investigate properly as he also expected to see a steel beam.

The wall is 3.2m wide and looks like a big mass of concrete resting on the brick at the end. Could it be a concrete lintel? Or is there a chance of an RSJ in there packed with concete? Joists above run parallel but there's also a brick wall above. Any advice welcome...

 

[noseall]

That's not a knock through. Its evidence of an old serving hatch or an old door opening.

If you intend taking the wall out then this serves no purpose in any case. Your new beam will sit higher.

 

[catlad]

A large magnet should give you some indication.

 

[tony1851]

Can't tell what it is, but it's likely to be original.
If that is a concrete beam, it looks cast in situ and would be unlikely to be a later alteration because of the sheer difficulty of supporting the wall above while pouring the concrete - and letting it go off.
My money's on Nosey's conclusion.

 

[^woody^]

I had a structural engineer over for something else and showed him and his advice was to get it propped and investigate properly as he also expected to see a steel beam.

I would expect an engineer not to expect a steel beam.

It's he a real one?

 

[togauk]

Thanks for all the comments.

That's not a knock through. Its evidence of an old serving hatch or an old door opening.

If you intend taking the wall out then this serves no purpose in any case. Your new beam will sit higher.

The opening is 2.5m wide and from the floor to 40cm off ceiling, too big for a serving hatch but could be an old doorway I guess.

I would expect an engineer not to expect a steel beam.

It's he a real one?

Yes, he did the calcs for another job but only had a quick glance at this. Do you think I should get another engineer or get a builder to have a look? Really I just want to know it's safe and if I can remove the rest of the plasterboard to open it up. The lack of an rsj threw me-the house is still standing and it's been like this for years no doubt so probably ok...

 

[^woody^]

Do you think I should get another engineer or get a builder to have a look?

It does appear to be as the others have stated - and existing opening with a cast in-situ concrete lintel .... so there would be no steel beam. I'm surprised that an engineer would think otherwise and suggest propping.

Are there any neighbouring houses that you could look in or ask about the layout? What about estate agent's past sales brochures for similar houses?

1950's houses would rarely have an open plan lounge/diner, so no steel beams. Normally a wall, and there may or may not be a doorway between lounge and dining room and concrete was the common lintel of the day.

If in doubt just get the engineer or someone experienced to have a better look.

 

[togauk]

Thanks woody, much appreciated.

 

[John D v2.0]

In our house they used some cast concrete in the upstairs floor for the fire place, it was held together with old iron gate strap hinges and a rim off a car wheel. I have no reason to think it's newer than the 20s house.
So you might find something non standard has held quite well over the years. The SE told me he's not too worried how it's stayed up so far, he's only concerned how the new bits stay up. On his say so we had to put some steel wind posts in to hold the spine wall in place.
What I'm saying is if it's not moving, it's fine, but changing it might be expensive as you need to prove the lot.

 

[garyo]

Have you taken a look at the sub-floor detail in the opening - there may be something down there that gives away whether there used to be a wall between the rooms.